package com.three.gateway.mobile.filter;

import com.alibaba.fastjson.JSON;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;

@Component
public class LoginFilter implements GlobalFilter, Ordered {
    @Autowired
    private RedisTemplate redisTemplate;//模板模式
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //1.获取request和response对象
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
        //2.获取请求路径
        String path = request.getURI().getPath();
        if(path.toLowerCase().contains("login") || path.toLowerCase().contains("register")){
            return chain.filter(exchange);
        }
        //3.获取token
        String token = request.getHeaders().getFirst("token");
        //4. 判断token是否为空
        if(token!=null && redisTemplate.hasKey("user::login::"+token)){
            redisTemplate.expire("user::login::"+token,30, TimeUnit.MINUTES);//刷新过期时间
            return chain.filter(exchange);
        }
        //3.2封装返回数据
        Map<String, Object> map = new HashMap<>();
        map.put("msg", "no login");
        map.put("code", 403);
        //3.3作JSON转换
        byte[] bytes = JSON.toJSONString(map).getBytes(StandardCharsets.UTF_8);
        //3.4调用bufferFactory方法,生成DataBuffer对象
        DataBuffer buffer = response.bufferFactory().wrap(bytes);

        //4.调用Mono中的just方法,返回要写给前端的JSON数据
        return response.writeWith(Mono.just(buffer));

    }
    @Override
    public int getOrder() {
        return 0;
    }
}
